Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!uunet!infonode!thidemah
From: thidemah@infonode.ingr.com (Hank Thidemann)
Newsgroups: comp.sys.sgi
Subject: Device driver question.
Message-ID: <1991Mar20.153727.13340@infonode.ingr.com>
Date: 20 Mar 91 15:37:27 GMT
Organization: Intergraph Corp. Huntsville, AL
Lines: 30


I have a couple of device driver questions:

   1) How would you unlock physical memory from a bottom
      half routine?

      I am calling userdma() from my ioctl() entry point
      and would like to unlock the pages in my interrupt
      handler.  Is there an equivalent of undma() that
      takes a pointer to a proc structure?  For various
      application specific reasons I can not use physio()
      or unlock the pages in the top half.


   2) How do you convert a user virtual address into a
      physical address?

      Since I can not use physio() I need to either
      generate the kernel virtual address myself and
      then call kvtophys() or map to a physical
      address directly.  This will be done in the top
      half.

   Thanks-

   Jon Raichek

   Optronics               ...uunet!jon@jon.optron.ingr.com
   7 Stuart Road           ...uunet!ingr!optron!jon!jon
   Chelmsford, MA 01824    508/250-8623